A singulation system for singulation or dicing electronic components, such as semiconductor substrates or packaged semiconductor devices, comprises at least a spindle system and a carrier support such as a chuck table. The cutting axis of the spindle system is orthogonal to the motion axis of the chuck table and a theta axis table is located on top of the chuck table. The spindle system typically includes either one or two high speed rotating shafts with a sawing blade each.
Dicing may be performed on the semiconductor substrate by moving the chuck table under a spindle axis while the sawing blade is cutting the semiconductor substrate on a carrier, such as a saw jig, on the chuck table. Cooling water is sprayed onto the sawing blade and the substrate during dicing. Chips, scrap and other debris are also formed during the process.
The chuck table is mounted on and guided by a slide while it is driven along its motion axis. In order to protect the slide and the motorized chuck table driver from the used machining water and from scrap and debris from the sawing process, bellows are provided that extend over and cover the slide on which the chuck table is driven. However, the bellows may not provide sufficient protection for the slide and the chuck table driver as explained below.
During the dicing process, scrap, debris and singulated substrates with very sharp edges may fly off the electronic components being cut, and drop between the folds of the bellows. This may cause the bellows to be cut and damaged. Water and debris may then drop through the cut bellows and damage the slide and chuck table driver. An expandable cover is thus preferably placed over the bellows as a shield from these sharp objects. The bellows protecting cover channels used machining water, scrap and debris along its longitudinal length to a receptacle positioned at an end of the cover. However, some of the debris may flow along the horizontal sides of the cover and drop off the sides of the cover. A drainage channel may further be located at each side of the bellows to collect such debris, which may subsequently be removed manually or directed to flow away with the water in the drainage channel. A problem is that, over a period of time, some of this debris accumulates and clogs the drainage channels. It is therefore necessary to intermittently halt the dicing machine in order to remove the accumulated debris.
U.S. Pat. No. 6,354,285 entitled “Attachment for a Dicing Saw” discloses an example of a collector for automatically collecting debris falling off the horizontal length of a bellows protecting cover during operation of a dicing saw. The collector includes drainage channels with sloping floors, each sloping downwards towards a debris container. Scrap and debris falling off from the horizontal sides of the bellows protecting cover collect in the drainage channels. A pressure means, such as a water jet or an air jet, is installed at the upper end of the sloping floor to provide a pressurized fluid to wash fallen debris down the sloping floor. While debris is automatically removed without the need to stop the dicing machine, this arrangement requires additional drainage channels and a pressure means to cause the debris to move into the debris container. It is desirable to devise a simpler drainage apparatus to collect and remove debris by eliminating these extra requirements.
Another prior art U.S. Pat. No. 6,500,058 entitled “Clogging-Free Drain System Installed in a Cutting Apparatus” discloses a water case for receiving used machining water and a drain pool for temporarily storing the used machining water from the water case before draining off this water. However, it would be more advantageous to be able to immediately channel the used water away from the system instead of having to provide a drain pool to store the water for a period of time.